1. Field of the Invention
The invention relates to a telephone instrument, more particularly to a telephone instrument with a built-in modem, and to a system for voice communications over the Internet.
2. Description of the Related Art
The Internet is the most widely used means for data communications throughout the world. With the use of the Internet, the cost of data communications has been reduced to the cost of connecting with a local Internet service provider.
To be able to access the Internet, a data network terminal, such as a computer, is connected to a telephone line via a modem. Without the presence of an adapter, the telephone line must be disconnected from the modem and then connected to a telephone instrument in order to be able to make a regular telephone call over a public switched telephone network. The act of switching connection of the telephone line between the modem and the telephone instrument is troublesome and results in a great deal of inconvenience to the user.
The use of a data network terminal for voice communications over the Internet is known in the art. With the appropriate software, the data network terminal can digitize the caller""s voice via a sound card, and then send the same in the form of an outgoing electronic mail using a standard modem over the Internet. The data network terminal can further reconstruct an incoming call from an incoming electronic mail for reproduction by the sound card. Through the Internet, the cost of making international calls can be dramatically reduced.
However, the conventional system for voice communications over the Internet suffers from some drawbacks. For instance, aside from a modem, the data network terminal must be provided with a sound card to make voice communications over the Internet possible. In addition, since sound pick-up and reproduction are accomplished via a microphone and a speaker that are connected to the sound card, the freedom of movement of the user is confined to within the vicinity of the data network terminal.
Therefore, the main object of the present invention is to provide a telephone instrument with a built-in modem device that is adapted to establish communication between a data network terminal and an Internet service provider through a telephone line.
Another object of the present invention is to provide a telephone instrument of the aforesaid type that can be used in a system for voice communications over the Internet.
A further object of the present invention is to provide a telephone instrument of the aforesaid type that has a cordless handset unit so that voice communication over the Internet can be made without severely limiting the freedom of movement of the user.
According to one aspect of the invention, a telephone instrument is adapted to be connected to a data network terminal and comprises:
a handset unit adapted for picking-up an outgoing call signal and for reproducing an incoming call signal;
a telephone base circuit operably associated with the handset unit for providing the incoming call signal to and for receiving the outgoing call signal from the handset unit; and
a modem device connected electrically to the telephone base circuit and operable in one of a voice transmission mode and a data transmission mode, the modem device including
telephone line connection means adapted to terminate one end of a telephone line,
network connection means adapted to establish data communication with the data network terminal,
signal routing means for routing signals among the telephone base circuit, the network connection means and the telephone line connection means,
voice/data detecting means adapted for initiating operation of the modem device in the voice transmission mode, wherein the signal routing means routes the outgoing call signal from the telephone base circuit to the telephone line via the telephone line connection means, and wherein the signal routing means routes the incoming call signal received from the telephone line via the telephone line connection means to the telephone base circuit, and
data communications means adapted to be activated by the data network terminal to operate the modem device in the data transmission mode, wherein the data communications means establishes communication between the data network terminal and an Internet service provider through the telephone line in response to a request to access the Internet from the data network terminal.
Preferably, the telephone instrument further comprises a signal coder/decoder connected electrically to the modem device. The data communications means is further adapted to be activated by the data network terminal to operate the modem device in an Internet voice communications mode. In the Internet voice communications mode, the signal routing means routes the outgoing call signal from the telephone base circuit to the signal coder/decoder. Then, the signal coder/decoder converts the outgoing call signal into encoded outgoing call data having a call data format that conforms to voice communications protocol through the Internet service provider. Subsequently, the signal routing means routes the encoded outgoing call data from the signal coder/decoder to the network connection means for reception by the data network terminal so that the encoded outgoing call data can be further converted into an encoded outgoing network signal having a network signal format that conforms to signal transmission protocol through the Internet service provider. Thereafter, the signal routing means routes the encoded outgoing network signal received from the data network terminal via the network connection means to the telephone line connection means for reception by the Internet service provider via the telephone line. Further, the signal routing means routes an encoded incoming network signal received by the telephone line connection means from the Internet service provider through the telephone line to the network connection means for reception by the data network terminal so that the encoded incoming network signal can be converted into encoded incoming call data. Then, the signal routing means routes the encoded incoming call data received from the data network terminal via the network connection means to the signal coder/decoder. Subsequently, the signal coder/decoder converts the encoded incoming call data into the incoming call signal. Thereafter, the signal routing means routes the incoming call signal from the signal coder/decoder to the telephone base circuit.
According to another aspect of the invention, a cordless handset is adapted to be connected to a data network terminal and comprises:
a wireless handset circuit adapted for picking-up an outgoing call signal and for reproducing an incoming call signal, the handset circuit being operable in a voice transmission mode, wherein the wireless handset circuit is adapted to form a wireless communications link with a telephone base unit for providing the outgoing call signal to and for receiving the incoming call signal from the telephone base unit; and
a modem device connected electrically to the handset circuit, the modem device including
telephone line connection means adapted to terminate one end of a telephone line,
network connection means adapted to establish data communication with the data network terminal,
signal routing means for routing signals among the handset circuit, the network connection means and the telephone line connection means, and
data communications means adapted to be activated by the data network terminal to operate the modem device in a data transmission mode, wherein the modem device disables operation of the handset circuit in the voice transmission mode, and wherein the data communications means establishes communication between the data network terminal and an Internet service provider through the telephone line in response to a request to access the Internet from the data network terminal.
Preferably, the cordless handset further comprises a signal coder/decoder connected electrically to the modem device. The data communications means is further adapted to be activated by the data network terminal to operate the modem device in an Internet voice communications mode. In the Internet voice communications mode, the signal routing means routes the outgoing call signal from the handset circuit to the signal coder/decoder. Then, the signal coder/decoder converts the outgoing call signal into encoded outgoing call data having a call data format that conforms to voice communications protocol through the Internet service provider. Subsequently, the signal routing means routes the encoded outgoing call data from the signal coder/decoder to the network connection means for reception by the data network terminal so that the encoded outgoing call data can be further converted into an encoded outgoing network signal having a network signal format that conforms to signal transmission protocol through the Internet service provider. Thereafter, the signal routing means routes the encoded outgoing network signal received from the data network terminal via the network connection means to the telephone line connection means for reception by the Internet service provider via the telephone line. Further, the signal routing means routes an encoded incoming network signal received by the telephone line connection means from the Internet service provider through the telephone line to the network connection means for reception by the data network terminal so that the encoded incoming network signal can be converted into encoded incoming call data. Then, the signal routing means routes the encoded incoming call data received from the data network terminal via the network connection means to the signal coder/decoder. Subsequently, the signal coder/decoder converts the encoded incoming call data into the incoming call signal. Thereafter, the signal routing means routes the incoming call signal from the signal coder/decoder to the handset circuit.